TFT array substrate and fabrication method thereof

Abstract

A TFT array substrate is provided. The TFT array substrate includes a gate electrode connected to a gate line; a source electrode connected to a data line, the data line crossing the gate line to define a pixel region; a drain electrode facing the source electrode with a channel interposed therebetween; a semiconductor layer forming the channel between the source electrode and the drain electrode; a channel passivation layer formed on the channel to protect the semiconductor layer; a pixel electrode disposed in the pixel region to contact with the drain electrode; a storage capacitor including the pixel electrode extending over the gate line to form a storage area on a gate insulating layer on which a semiconductor layer pattern and a metal layer pattern are stacked; a gate pad extending from the gate line; and a data pad connected to the data line.

Description

[0001] This application claims the benefit of Korean Patent Application No. 117243 / 2004, filed on Dec. 30, 2004, which is hereby incorporated by reference for all purposes as if fully set forth herein. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a thin film transistor (TFT) array substrate, and more particularly, to a TFT array substrate and a fabrication method thereof capable of protecting TFTs without a passivation layer and preventing galvanic corrosion of a data or gate pad. [0004] 2. Discussion of the Related Art [0005] A liquid crystal display (LCD) displays an image by controlling the light transmittance of liquid crystal (LC) using an electric field. [0006] The LCD drives the LC using an electric field generated between a pixel electrode and a common electrode respectively disposed on an upper substrate and a lower substrate facing each other. [0007] The LCD has a TFT array substrate (lower array substrate) and a colo...

AI Technical Summary

Benefits of technology

[0043] An advantage of the present invention is to provide a TFT array substrate and a fabrication method thereof, which can protect TFTs without a passivation layer and reduce the manufacturing cost and the number of the required masks.

[0044] Another advantage of the present invention is to provide a TFT array substrate and a fabrication method thereof, which can prevent galvanic corrosion due to opening of a data pad by forming the data pad in a jumping structure of a gate metal pattern and a data metal pattern.

[0045] A further another advantage of the present invention is to provide a TFT array substrate and a fabrication method thereof, which can reduce the number of the required processes by separating even / odd data lines to form a static electricity prevention structure.

[0046] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

[0047] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a TFT array substrate including: a gate electrode connected to a gate line; a source electrode connected to a data line, the data line crossing the gate line to define a pixel region; a drain electrode facing the source electrode with a channel interposed therebetween; a semiconductor layer forming the channel between the source electrode and the drain electrode; a channel passivation layer formed on the channel to protect the semiconductor layer; a pixel electrode disposed in the pixel region to contact with the drain electrode; a storage capacitor including the pixel electrode extending over the gate line to form a storage area on a gate insulating layer on which a semiconductor layer pattern and a metal layer pattern are stacked; a gate pad extending from the gate line; and a data pad connected to the data line.

[0048] In another aspect of the present invention, there is provided a method of fabricating a TFT array substrate including: forming a gate electrode, a gate line, a gate pad lower electrode, and a data pad lower electrode on a substrate; forming a gate insulating layer, a first semiconductor layer, a second semiconductor layer, and a data metal layer on the gate electrode; patterning the gate insulating layer, the first and second semiconductor layers, and the data metal layer to form the gate line, the data line, a data line, a TFT region, a gate pad, and a data pad and to form a cut area exposing the gate insulating layer one the gate line; coating a transparent conductive layer on the substrate and patterning the transparent conductive layer to form source and drain electrodes, a first semiconductor layer forming a channel therebetween, a pixel electrode contacting with the drain electrode, a gate pad upper electrode, and a data pad upper electrode in the TFT region; and a channel passivation layer on the first semiconductor layer corresponding to the channel.

Problems solved by technology

In the LCD, because fabrication of the TFT array substrate requires a semiconductor process and a plurality of mask processes, the manufacturing process thereof is complicated and thus manufacturing costs increase.

Because the PECVD apparatus, the spin coating apparatus, or the spinless coating apparatus are required to form the passivation layer 18 as descried above, the manufacturing cost increases.

Also, because the data pad is opened when the passivation layer is formed, a defect (e.g., galvanic corrosion of a data pad) may be generated during a subsequent process.

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